A switch arrangement is known from U.S. Pat. No. 4,587,390. This arrangement includes a housing which contains a spring force drive on which three tubular insulating support frames are arranged to stand. In each insulating support frame, a vacuum switching tube is mounted, the contacts of which are connected to one connection conductor, each which penetrates the respective insulating support frame in the radial direction. In the housing of the spring force drive, two parallel shields are provided which are laterally spaced apart and on which the drive parts of the spring force drive are supported. Each moving contact of the vacuum switching tubes is effectively connected via one linkage, each to the output member of the spring force drive which is common to all poles. This switch arrangement includes many individual parts and is expensive in its construction and assembly.
Furthermore, a vacuum switch arrangement with a mobile framework is known from EP Patent Specification 0,060,051 which corresponds to U.S. Pat. No. 4,449,021. On this framework, a single-piece insulating support frame is mounted backwards, which includes three adjacently arranged recessed which are open towards the front and in which one vacuum switching tube is mounted in each recess. On the framework, a housing is also mounted in which a drive is arranged, the output part of which is effectively connected via one linkage, each to the moving contact of each vacuum switching tube, a double lever of each linkage being supported on extensions of the insulating support frame. Although the insulating support frame is handling several functions, the construction of the entire switch arrangement is still expensive.